1. Field of the Invention
This invention relates generally to a safety net structure and, particularly, to a perimeter safety net including its supporting array, as the structure is both synthesized and erected in its preferred and alternate embodiments.
2. Relevant Art Discussion
Perimeter safety net systems are known in the art and are distinctive over their drop net analogs. The latter are generally suspended over or between trusses, cantilevered supports and the like in order to provide a safety catch or stop for dropped or falling items. The former, that with which I am concerned, is provided primarily to prevent people from falling from precipitous places such as buildings or geological ledges, superstructures and, particularly, aircraft surfaces.
Illustrative of relevant art that I have discovered or become acquainted with is a fall protection device made by SINCO (.TM.) that provides a stanchion mounting means. The stanchion is cantilevered off a two-jaw base that engages a flange of a girder or I-beam. Safety securement of the stanchion is had by extending a strap bearing an end hook to and over an opposing flange of the girder or beam and fixedly cinching the strap to the stanchion. Finally, a safety line is drawn between at least two such stanchions and workers are tethered to the safety line. Since a primary focus of my invention is to afford perimeter safety on an aircraft surface, the aforesaid "tethered" approach is unsatisfactory because the apparatus would necessitate excessive changing of tethering positions, to provide reasonable contraint, and by so doing would restrict the worker's lateral range. Engaging the jaws on aircraft surfaces appears impossible.
Perimeter system components, as purportedly disclosed in U.S. Pat. No. 3,949,843 consist primarily in cantilevered stanchions and the webs or nets secured thereto. Webs or nets are connected by snap hooks to welded eyes, a device well know in this and several construction and marine fields. The stanchion (termed "arm") is piviotally secured to a base plate that is boltable to a horizontal surface. By virtue of the pivotal securement, as well as base plate mounting, the stanchion may be oriented to most positions with respect to the horizontal or vertical. Thus the disclosed apparatus may lend itself to rigging with perimeter or dorp nets, but according to the instructions that I have read, drop net rigging is preferred. This limitation appears to obtain simply because no provision is made to literally secure the stanchion in a fixed or totally stationary posture. Movement of the stanchion is of little consequence when a (horizontal) drop net is used, but such would prove disasterous on an aircraft surface or any time the net is vertically rigged to prevent horizontal translation such as in walking.
My requirements cannot be satisfactorily fulfilled by prior art devices, so I have developed a stanchion assembly that may be fixed by conventional bolting or strapping mechanisms but in which each stanchion can be rigidly fixed against movement or collapse. Further, the stanchions of my invention can accomodate slope mounting while still presenting a perpendicular posture relative to the walking surface or one inclined thereto.